edu.ucar.opensky::articles:25753 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T22:39:12.125237 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7n87fkf https://doi.org/10.7302/6q48-dk51 https Related Dataset #1 Paleoclimate simulations of South America during the early Eocene and middle Miocene Evolution of the Atlantic Intertropical Convergence Zone, and the South American and African monsoons over the past 95-myr and their impact on the tropical rainforests 2022-07-21T00:00:00Z publication https://n2t.org/ark:/85065/d7n87fkf https://doi.org/10.1029/2021PA004383 Acosta, R. P. author Ladant, J. author Zhu, Jiang author Poulsen, C. J. author UCAR/NCAR - Library publisher The widening of the South Atlantic Basin led to the reorganization of regional atmospheric and oceanic circulations. However, the response of the Atlantic Intertropical Convergence Zone (ITCZ), and South American and African monsoons across paleoclimate states, especially under constant paleogeographic and climatic changes, has not been well understood. Here we report on paleoclimate simulations of the Cenomanian (similar to 95 Ma), early Eocene (similar to 55 Ma), and middle Miocene (similar to 14 Ma) using the Community Earth System Model version 1.2 to understand how the migration of the South American and African continents to their modern-day positions, uplift of the Andes and East African Rift Zone, and the decline of atmospheric CO2 changed the Atlantic ITCZ, and the South American and African monsoons and rainforests. Our work demonstrates that the South Atlantic widening developed the Atlantic ITCZ. The South Atlantic widening and Andean orogeny led to a stronger South American monsoon. We find the orogeny of the East African Rift Zone is the primary mechanism that strengthened the East African monsoon, whereas the West African monsoon became weaker through time as West Africa migrated toward the subtropics and CO2 levels fell below 500 ppm. We utilize the Koppen-Geiger Climate Classification as an indicator for maximum rainforest extent. We find that during the Cenomanian and early Eocene, a Pan-African rainforest existed, while the Amazon rainforest was restricted toward the northwestern corner of South America. During the middle Miocene, the Pan-African rainforest was reduced to near its modern-day size, while the Amazon rainforest expanded eastward. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation